单选题 设X~N(8,0.42),从ξ中抽取样本(X1,X2,…,X8),则X~(    )
   A.N(1,0.42)  B.N(1,0.02)   C.N(8,0.02)   D.N(8,0.022)
【正确答案】 C
【答案解析】